188 research outputs found

    Aseismic and seismic impact on development of soft-sediment deformation structures in deep-marine sand-shaly Crocker fan in Sabah, NW Borneo

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    Abstract Soft-sediment deformation structures are present within the deep-marine fan of the West Crocker Formation, Sabah Basin, NW Borneo. Focus of this study is to highlight the impact of seismic and aseismic activities on the development of these structures and their distribution in deep-marine fan. Twenty-nine types of deformation structures were identified during the study of twelve exposed sections. These structures were grouped into five categories: i) water-escape structures, ii) sole marks, iii) clastic intrusions, iv) deformed laminations, and v) syn-depositional brittle and ductile deformation structures. The sediment deformation is interpreted to be caused either by aseismic processes like slope failure, gravity collapse, sediment overloading, density gradient, seismic induced mechanisms such as earthquakes, tectonic uplift, or combined effect of seismic and aseismic events. These structures are classified based on type of features developed during semi-consolidated phase of rock deposition. The seismite structures i.e., clastic intrusions, deformed laminations, and syn-depositional structures are correlated with active collisional tectonics during the Late Paleogene times in the Sabah Basin. In the present work, a generalized conceptual model has also been proposed for the development of soft-sediment deformation structures in a submarine fan environment. Dewatering structurers and rapid sedimentation features are associated with inner fan, load and flame structures are present within middle fan, while contorted layers, slumps and mass-transport deposits are linked with distal fan settings

    Complementarity of Semileptonic BB to K2(1430)K_2^*(1430) and K(892)K^*(892) Decays in the Standard Model with Fourth Generation

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    The BK2(1430)l+lB\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-} (l=μ,τ)(l=\mu,\tau) decays are analyzed in the Standard Model extended to fourth generation of quarks (SM4). The decay rate, forward-backward asymmetry, lepton polarization asymmetries and the helicity fractions of the final state K2(1430)K^{*}_{2}(1430) meson are obtained using the form factors calculated in the light cone sum rules (LCSR) approach. We have utilized the constraints on different fourth generation parameters obtained from the experimental information on KK, BB and DD decays and from the electroweak precision data to explore their impact on the BK2(1430)l+lB\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-} decay. We find that the values of above mentioned physical observables deviate deviate significantly from their minimal SM predications. We also identify a number of correlations between various observables in BK2(1430)l+lB\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-} and BK(892)l+lB\rightarrow K^{\ast}(892)l^{+}l^{-} decays. Therefore a combined analysis of these two decays will compliment each other in the searches of SM4 effects in flavor physics.Comment: 28 pages, 12 figure

    Age-based sensitivity analysis on cardiac hemodynamics using lumped-parameter modelling

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    Age is a major risk for heart failure, which is associated with the reduction in ventricular compliance, increase in arterial stiffening, and increase in systemic vascular resistance. In this study, a lumped-parameter model is used to investigate the effect of aging on the possibility of heart failure occurrence. Model parameters including the systemic and pulmonary arterial compliance and resistance, and the left ventricular elastance are calculated for different ages using a ratio-based method. These parameters are then used in the lumped-parameter model. Our findings show that as age increases, there is a leftward and a rightward shift in the left ventricle and right ventricle pressure-volume loops, respectively. For the left ventricle, there is a decrease in stroke volume and an increase in ventricular pressure as the age increases. This correlates with the occurrence of arterial hypertension in the older population. Meanwhile, the right ventricular pressure is maintained as the population gets older, despite the increase in the stroke volume. This is possibly due to the shift in intraventricular septum that causes an enlargement of the right ventricle as the age increases. This study provides understanding on the effect of age on the occurrence of heart failure.This study demonstrates the relationship of aging with cardiac hemodynamics, which provides the potential risk of heart failure occurrence. Although there are many risk factors that can cause heart failure, aging has been strongly associated with its occurrence. Understanding how age affects heart failure can help to differentiate them from other effects such as dietary, gender, and early cardiovascular diseases including arrhythmia and myocardial infarction

    A two-element planar multiple input multiple output array for ultra-wideband applications

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    In this article, a planar monopole two-element multiple input multiple output (MIMO) array has been designed and characterized with the intention of ultra-wideband (UWB) applications. The array has a voltage standing wave ratio (VSWR) working bandwidth (BW) of 13.258 GHz between 3.394-16.652 GHz, with a fractional BW (FBW) of 132.28% with respect to a center frequency of 10.023 GHz. The two elements of the MIMO array are 900 polarizations mismatched for better isolation. Consequently, less than 20 dB of isolation has been achieved throughout the entire BW. Also observed was a good combined realized peak gain of up to 5.85 dBi and total efficiency of greater than 85%. For MIMO performance key parameters, the array exhibits the envelope correlation coefficient (ECC) 9.983, total active reflection coefficient (TARC) <0.445, mean effective gain difference (MEG12) ≈0 dB, and the channel capacity loss (CCL) <0.4 bps/Hz. This design would encourage designers to create high-performance MIMO antennas for UWB frequency-related applications

    Pain interference level and its effects on patients' quality of life and depression: a study on breast cancer survivors in Hospital Kuala Lumpur, Malaysia

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    Introduction: Cancer pain is a complex experience and is one of the most common and distressing symptom of breast cancer which affects patients’ functioning in daily activities, their quality of life (QOL), and mood. Yet, there is a great lack of data on breast cancer and pain in Malaysia. Methods: A cross-sectional study using the Breast Cancer Patient Version of Quality of Life (QOL) Instrument (translated into Malay) and Depression Anxiety and Stress Scale (DASS) were conducted on 87 female breast cancer patients to investigate the impact of pain interference level on their quality of life and depressive level. Results: The patients were divided into 4 groups based on their rating of how pain and aches have been a problem to them (i.e not a problem [n=18 (20.7%)], mild[n=29 (33.3%)], moderate [n=18 (20.7%)] and severe [n=22(25.3%). Pain and aches ware reported to be the most severe interference problems in QOL physical domain by patients (mean=5.8, SD=2.8), followed by fatigue (mean=6.0, SD=3.1) and sleep changes (mean=6.2, SD=3.5). Patients who reported that pain and aches had severely affected them showed significantly lower score on many aspects of quality of life (Fs > 5, p < 0.005; p < 0.0001) and patients reported pain was not a problem at all demonstrated highest score on all aspects of QOL. Patients with most severe pain interference level showed highest depressive score [F (3, 84) =3, p < 0.05]. Conclusion: The study underscores the impact of pain interference on patients’ quality of life and depressive level. The pain assessment deserves significant attention and therefore a comprehensive biopsychosocial assessment of pain to rule out any related underlying issues is warranted in the management of breast cancer to ensure appropriate intervention given to the patients

    Reconstruction of some cosmological models in f(R,T) gravity

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    In this paper, we reconstruct cosmological models in the framework of f(R,T)f(R,T) gravity, where RR is the Ricci scalar and TT is the trace of the stress-energy tensor. We show that the dust fluid reproduces Λ\Lambda CDM, phantom-non-phantom era and the phantom cosmology. Further, we reconstruct different cosmological models including, Chaplygin gas, scalar field with some specific forms of f(R,T)f(R,T). Our numerical simulation for Hubble parameter shows good agreement with the BAO observational data for low redshifts z<2z<2.Comment: 12 pages, 2 figure

    Genetic variation in strigolactone production and tillering in rice and its effect on Striga hermonthica infection

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    Tillering in cereals is a complex process in the regulation of which also signals from the roots in the form of strigolactones play an important role. The strigolactones are signalling molecules that are secreted into the rhizosphere where they act as germination stimulants for root parasitic plants and hyphal branching factors for arbuscular mycorrhizal fungi. On the other hand, they are also transported from the roots to the shoot where they inhibit tillering or branching. In the present study, the genetic variation in strigolactone production and tillering phenotype was studied in twenty rice varieties collected from all over the world and correlated with S. hermonthica infection. Rice cultivars like IAC 165, IAC 1246, Gangweondo and Kinko produced high amounts of the strigolactones orobanchol, 2′-epi-5-deoxystrigol and three methoxy-5-deoxystrigol isomers and displayed low amounts of tillers. These varieties induced high S. hermonthica germination, attachment, emergence as well as dry biomass. In contrast, rice cultivars such as Super Basmati, TN 1, Anakila and Agee displayed high tillering in combination with low production of the aforementioned strigolactones. These varieties induced only low S. hermonthica germination, attachment, emergence and dry biomass. Statistical analysis across all the varieties confirmed a positive correlation between strigolactone production and S. hermonthica infection and a negative relationship with tillering. These results show that genetic variation in tillering capacity is the result of genetic variation in strigolactone production and hence could be a helpful tool in selecting rice cultivars that are less susceptible to S. hermonthica infection

    Investigation of Pulse electric field effect on HeLa cells alignment properties on extracellular matrix protein patterned surface

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    YesCell behavior in terms of adhesion, orientation and guidance, on extracellular matrix (ECM) molecules including collagen, fibronectin and laminin can be examined using micro contact printing (MCP). These cell adhesion proteins can direct cellular adhesion, migration, differentiation and network formation in-vitro. This study investigates the effect of microcontact printed ECM protein, namely fibronectin, on alignment and morphology of HeLa cells cultured in-vitro. Fibronectin was stamped on plain glass cover slips to create patterns of 25μm, 50μm and 100μm width. However, HeLa cells seeded on 50μm induced the best alignment on fibronectin pattern (7.66° ±1.55SD). As a consequence of this, 50μm wide fibronectin pattern was used to see how fibronectin induced cell guidance of HeLa cells was influenced by 100μs and single pulse electric fields (PEF) of 1kV/cm. The results indicates that cells aligned more under pulse electric field exposure (2.33° ±1.52SD) on fibronectin pattern substrate. Thus, PEF usage on biological cells would appear to enhance cell surface attachment and cell guidance. Understanding this further may have applications in enhancing tissue graft generation and potentially wound repair.Ministry of Higher Education Malaysia and UTHM Tier 1 Research Grant (U865

    Aquilaria malaccensis polyploids as improved planting materials

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    Aquilaria malaccensis is an agarwood-producing timber species used in many traditional remedies and modern therapeutic treatments and perfume industries. In this study, we aimed to enhance A. malaccensis phytochemical content through in-vitro polyploidisation. Shoot tip and nodal segment from 8-week-old in-vitro A. malaccensis plantlets were treated with different concentrations of colchicine and trifluralin at various exposure times to obtain polyploids. Tetraploid plantlets (10%) was obtained using nodal segment explants treated with 0.1 mM trifluralin at 120 hours. Chemical profiling of diploid and tetraploid samples (leaf, stem and root) was evaluated separately using headspace-solid phase microextraction (HS-SPME) combined with gas chromatograph mass spectrometry (GCMS). Phytochemical content increased in tetraploid, particularly in stem whereby the total phytochemical contents were 43.19% in tetraploid compared with 5.87% in diploid. The HS-SPME-GCMS analyses showed that tetraploid stem contained high levels of sesquiterpenoids found in agarwood oil such as α-eudesmol (18.3%), α-gurjunene (8.61%) and γ-gurjunene (6.22%). On the other hand, aromadendrene (2.49%) and α-humulene (3.38%) were detected in diploid samples. Tetraploid leaf samples were observed to contain α-humulene (3.79%) while diploid only contained (2E) tridecenol (19%). There were no significant differences between diploid and tetraploid in terms of total phytochemical content in root samples. Nevertheless, high sesquiterpenoid content, γ-gurjunene (14.0%), was detected in tetraploid sample while γ-muurolene (2.96%), in diploid. α-Guaiene content was higher in root samples of diploid (6.49%) than tetraploid (1.09%). These results demonstrated that tetraploid plantlets led to higher yield of total phytochemical content and might facilitate production of high quality A. malaccensis clones

    The longer-term effects of access to HIV self-tests on HIV testing frequency in high-risk gay and bisexual men: follow-up data from a randomised controlled trial

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    Background: A wait-list randomised controlled trial in Australia (FORTH) in high-risk gay and bisexual men (GBM) showed access to free HIV self-tests (HIVSTs) doubled the frequency of HIV testing in year 1 to reach guideline recommended levels of 4 tests per year, compared to two tests per year in the standard-care arm (facility-based testing). In year 2, men in both arms had access to HIVSTs. We assessed if the effect was maintained for a further 12 months. Methods: Participants included GBM reporting condomless anal intercourse or > 5 male partners in the past 3 months. We included men who had completed at least one survey in both year 1 and 2 and calculated the mean tests per person, based on the validated self-report and clinic records. We used Poisson regression and random effects Poisson regression models to compare the overall testing frequency by study arm, year and testing modality (HIVST/facility-based test). Findings: Overall, 362 men completed at least one survey in year 1 and 343 in year 2. Among men in the intervention arm (access to HIVSTs in both years), the mean number of HIV tests in year 2 (3⋅7 overall, 2⋅3 facility-based tests, 1⋅4 HIVSTs) was lower compared to year 1 (4⋅1 overall, 1⋅7 facility-based tests, 2⋅4 HIVSTs) (RR:0⋅84, 95% CI:0⋅75-0⋅95, p=0⋅002), but higher than the standard-care arm in year 1 (2⋅0 overall, RR:1⋅71, 95% CI:1⋅48-1.97, p<0⋅001). Findings were not different when stratified by sociodemographic characteristics or recent high risk sexual history. Interpretation: In year 2, fewer HIVSTs were used on average compared to year 1, but access to free HIVSTs enabled more men to maintain higher HIV testing frequency, compared with facility-based testing only. HIV self-testing should be a key component of HIV testing and prevention strategies. Funding:: This work was supported by grant 568971 from the National Health and Medical Research Council of Australia
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